The process pertains to a method to produce polystyrene with reduced flammability by polymerization of styrene in aqueous suspension. As flame retarding additives are used halogen-free compounds. Suspension polymerization of polystyrene is performed in the presence of initiator, by adding a solution or styrene dispersion of phosphorous burning reducing additives to water mixed with a suspension stabilizer. There can also be added a modified or unmodified mineral with nanometric layered structure, especially modified montmorillonite and in justified cases also porophor. The product obtained is characterized favorable parameters of horizontal and vertical flammability (according to PN-EN-60695-11-10:2002 standard) and favorable parameters of oxygen index (according to ASTM D 2863-97 standard).

Advantages of the technology offered

In the industrial practice, flammability of polystyrene obtained with the suspension polymerization method is reduced mainly with halogen additives, e.g. bromine compounds.

The technology offered reduces flammability of polystyrene in a pro-ecological way, without using noxious, halogen flame retardants.

Equipment

The process can be performed using industrially available apparatus to produce polystyrene.

The proposed solution is competitive in relation to currently used methods to reduce polystyrene flammability with halogen additives, whose application is now being restricted by the European Union legislation.